Are you running the rci skid?
Just got off the phone with RCI they have redesigned their front skid to work with or without diff drop no spacers needed. I'll let you all know how it fits.
I know this is an old thread, sorry for the breach of etiquette in reopening it. I just installed RCI skids and don't have a lift but will be getting one in the near future. Did you need to use spacers with the diff drop?